James Hansen’s 1988 climate predictions have proved to be remarkably accurate

In 1988, Dr. James Hansen testified in front of Congress about the future dangers of climate change caused by human activity. That same year, the results of a study released by Hansen and his team at the Goddard Institute for Space Studies detailed three possible scenarios for possible future warming. Their middle-of-the-road prediction has proved to be remarkably accurate over the past 30 years.

Changes in the human effects that influence Earth’s global energy imbalance (a.k.a. ‘anthropogenic radiative forcings’) have in reality been closest to Hansen’s Scenario B, but about 20-30% weaker thanks to the success of the Montreal Protocol in phasing out chlorofluorocarbons (CFCs). Hansen’s climate model projected that under Scenario B, global surface air temperatures would warm about 0.84°C between 1988 and 2017. But with a global energy imbalance 20-30% lower, it would have predicted a global surface warming closer to 0.6-0.7°C by this year.

The actual 1988-2017 temperature increase was about 0.6°C. Hansen’s 1988 global climate model was almost spot-on.